Positron Emission Tomography (PET) with (l8F)-fluorodeoxyglucose (FDG) allows us to obtain anatomical data (e.g., axial transverse or coronal images of the brain) as well as dynamic functional data (such as regional cerebral glucose consumption rate; measurements of the storage, degradation and turnover of tagged metabolites; follow-through of the movement of the CSF in the deep intracranial cavities). The unique property of PET is that it provides physiologic information not available with any other imaging procedure. Since June l982 we have been using the new high-resolution, high-sensitivity scanner built in our section, the Neuro-PET. The performance of this scanner has exceeded all our expectations. This device has allowed new applications of the PET technique.